By Joseph Brownstein  |   August 20, 2013 12:32pm

A depressed-looking man sits with his hands on his head.

It can be difficult to tell when a person is contemplating suicide -- people may be reluctant to speak about it. But now, researchers say they may have a new tool that reveals suicidal thoughts with a blood test.

The researchers found the levels of certain molecules in the blood differed when people with bipolar disorder were having suicidal thoughts, and they were able to confirm their findings in the bodies of men who had recently committed suicide.

"We found some blood biomarkers, some changes in molecules in the blood, that are associated with having a high suicidal risk, and then we validated those changes in blood from suicide completers," said Dr. Alexander Niculescu III, an associate professor of psychiatry and medical neuroscience at the Indiana University School of Medicine.

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